                    :health_check_type "EC2"
                    :health_check_grace_period 20
                    :subnets public-subnets
+                   :lifecycle {:create_before_destroy true}
                    :elb [{:name "PublicSlaveServerGroup"
                           :health_check {:healthy_threshold 2
                                          :unhealthy_threshold 2

                   :health_check_type "EC2" ;; or "ELB"?
                   :health_check_grace_period 20
                   :subnets private-subnets
                   :elb []
                   })
             ))))

                   :health_check_grace_period 20
                   :root_block_device {:volume_size 20}
                   :subnets public-subnets
                   :lifecycle {:create_before_destroy true}
                   :elb [{:name "MasterServerGroup"
                          :health_check {:healthy_threshold 2
                                         :unhealthy_threshold 3
